Prime Minister Andrej Plenkovic, who is the party leader, said "that is their choice."

"It is good that we have approved the convention," said Plenkovic. "We should work to reduce the divisions."

Plenkovic also insisted that the massive protest in Split against the convention "was about a different agenda," implying the conservatives want to topple his government.

Since joining the EU in 2013, Croatia has been drifting toward the right, including some who deny the Holocaust and have re-appraised the Ustasha regime that ruled the country during WWII when tens of thousands of Jews, Serbs and Roma perished in concentration camps.

The document was adopted by the Council of Europe in 2011 in a bid to fight violence against women throughout Europe, but until Friday it had not been ratified by Croatia's parliament, when it became a law.